Register for and file your Self Assessment tax return

Register if you're not self-employed

If you have to send a tax return and didn’t send one last year, you need to register for Self Assessment by 5 October.

If you’ve sent a return before

You’ll need the 10-digit Unique Taxpayer Reference (UTR) from when you registered previously. You can find your UTR if you’ve lost it.

After you register, sign in to the online account you set up previously and file your tax return.

If you haven’t sent a return before

After you register, you’ll get a letter within 10 working days (21 if you’re abroad) which will contain your Unique Taxpayer Reference (UTR).

You’ll need to:

You’ll get an activation code in the post within 10 working days of enrolling (21 if you’re abroad). When you have your code, sign in to your online account to file your return online.

You can replace an activation code if you don’t receive it or you lose it.